(1) Field of the Invention
The present invention relates to a thinning of a liquid crystal display apparatus.
(2) Description of Related Art
As a liquid crystal display apparatus in accordance with a prior art, there is disclosed a liquid crystal display apparatus having a liquid crystal panel PNL displaying an image, and a lighting apparatus BL arranged in a back surface of the liquid crystal panel PNL and emitting a white light to the liquid crystal panel PNL, and structured such that the lighting apparatus BL has a fluorescent tube CFL, a reflection member arranged in a back surface of the fluorescent tube CFL and reflecting in a diffusion manner the white light from the fluorescent tube CFL, and a diffusion plate DEP arranged in a front surface of the fluorescent tube CFL and transmitting the white light from the fluorescent tube CFL in a diffusion manner, as described in patent document 1 (JP-A-2005-347062).
In the conventional liquid crystal display apparatus mentioned above, since the diffusion plate is thermally expanded by a heat generation of the fluorescent tube, the thermal expansion of the surface which is close to the fluorescent tube becomes greater than the thermal expansion of the surface which is far from the fluorescent tube, and the diffusion plate is deformed convex toward the fluorescent tube side. If the diffusion plate is deformed convex toward the fluorescent tube side, the diffusion distance becomes smaller than the minimum diffusion distance in the case that the height from the reflection member to the fluorescent tube is aligned with the minimum diffusion distance capable of suppressing a brightness unevenness. Accordingly, there is generated a problem that the light generation portion of the fluorescent tube is viewed as the brightness unevenness. Particularly, since a sensitivity about a uniformity of the emitted light becomes higher with respect to the dispersion of the diffusion distance in accordance that the height becomes small by being aligned with the minimum diffusion distance, the uniformity of the emitted light from the fluorescent tube can not be secured only by a little convex deformation of the diffusion plate toward the fluorescent tube side, so that there is generated a problem that the light generation portion of the fluorescent tube is viewed as the brightness unevenness.
For example, in the case that the diffusion distance about 20 mm is made equal to or less than 10 mm because the minimum diffusion distance is equal to or less than 10 mm, the diffusion plate is deformed convex to the fluorescent tube side, and the uniformity of the emitted light from the fluorescent tube can not be secured, only by generation of a strain equal to or less than 1 mm, so that there is generated a problem that the light generation portion of the fluorescent tube is viewed as the brightness unevenness.